Copyright — Defense— - Affirmative Defense - Statute of Limitations is a defense that is available to an alleged infringed in a copyright infringement action. This defense is based on the fact that the right to sue for infringement of a copyright is limited by a certain amount of time. The Statute of Limitations (SOL) for copyright infringement actions is three years from the date of the infringement. The Statute of Limitations defense can be used to prevent an alleged infringed from being held liable for copyright infringement if the infringement occurred more than three years prior to the action being brought. If the alleged infringed can prove that the infringement occurred more than three years ago and that they had no knowledge of it at the time, they may be able to avoid liability for the infringement. There are two types of Statute of Limitations defenses available to alleged infringes: the "discovery rule" and the "caches rule." The discovery rule allows an alleged infringed to avoid liability if they did not discover the infringement until after the three-year SOL had expired. The caches rule allows an alleged infringed to avoid liability if there was an unreasonable amount of delay before the action was brought. Overall, the Statute of Limitations defense provides an alleged infringed with a potential defense to copyright infringement claims if they can prove that the infringing activity occurred more than three years prior to the commencement of the action.